This invention relates to a detent mechanism for clutches and more particularly to an improved detent mechanism for the dog clutch of a marine transmission.
Many forms of transmissions, such as the forward/neutral/reverse transmission of a marine drive employ dog clutches for coupling rotating members together. Such dog clutches normally employ a form of detent mechanism that is opertive to engage the clutch element in one of its positions. Normally, the detent mechanism holds the clutch in a released condition. It is desirable, however, to insure quick shifting of the dog clutch jaws into engagement by employing some mechanism for urging the dog clutching element to its engaged position when it has moved from its released position. Frequently, the same detent mechanism is used to exert an axial thrust on the dog clutch element in addition to serving the function of retaining the dog clutch element in its neutral position. Normally, the detent ball operates with a recess for holding the dog clutch element in its released position and with a cam surface for exerting an axial force upon the dog clutch element to move it into engagement.
With prior art type of devices employing a single detent ball for performing both holding and accelerating functions, the clutch element must be moved a substantial distance from its neutral position before the thrust effecting device can be operative. This is a result of the geometric relationships of the arrangement employing a single ball for both purposes. That is, the detent ball must come out of its retaining groove and travel a sufficient distance so as to engage the cam surface before the thrust operation can occur. Of course, such arrangements require fairly substantial travel and, therefore, have many disadvantages.
It is, therefore, a principal object of this invention to provide an improved detent mechanism for a dog clutch.
It is a further object of this invention to provide a dog clutch detent mechanism that will hold the dog clutch element in a neutral condition and which will exert a thrust on the clutch element moving it toward its engaged position as soon as the clutch element has moved only slightly from its neutral position.
In connection with the design of dog clutches and the associated detent mechanisms, it is desirable to provide a very compact arrangement. Frequently, the detent mechanisms must be contained within the clutch element itself and this has required the use of the single detent type of mechanisms as aforedescribed.
It is, therefore, a still further object of this invention to provide an improved and compact detent arrangement for a dog clutch that acts to hold the clutch in a neutral position and which also exerts an actuating thrust on the clutch element once it has moved only slightly from the neutral position.
It is a still further object of the invention to provide an improved shifting mechanism for marine drives.